[GRASSLIST:602] Re: GOES images - again

Daniel Victoria daniel.victoria at gmail.com
Thu Apr 6 09:16:52 EDT 2006


What I'm trying to do is to convert the goes coordinates file into a
POINTS file for an imagery group and then use i.rectify.

Do you think that's doable? So far I have only got really bad results
but probably due to the fact that I'm a lousy programer and I'm having
a hard time understanding the way the coordinate file is stored...

Thanks

Daniel

On 4/5/06, Glynn Clements <glynn at gclements.plus.com> wrote:
>
> Daniel Victoria wrote:
>
> > > > I'm trying to import GOES tif images that have no georeferencing. The
> > > > georef information is in a separate file which I finaly opened. It
> > > > contains the lat and lon for every cell in the GOES images. The
> > > > problem is, I just can't seem to get the lat/lon information into the
> > > > TIF files. Is there any way to do this? gdalwarp? gdal_translate?
> > > > i.points?
> > >
> > > add GCPs with gdal_translate, then gdalwarp?
> >
> > but my control points are in a huge text list and the switch -gcp in
> > gdal_translate does not accept that. So, I have to enter the corner
> > points by hand? Or is there a way to make gdal_translate read from a
> > text file (all 1200000 points)?
>
> I don't think that gdal_translate was designed to handle such large
> numbers of control points.
>
> You could import your data as a vector point map then use v.surf.rst.
>
> You would probably need to match the coordinates with the cell values
> manually (e.g. exporting the raster with r.out.ascii, importing the
> coordinates along with the r.out.ascii output into a DBMS, then
> joining the two tables).
>
> Alternatively, you may be able to get adequate results by using a
> small sample of the control points and gdalwarp's -tps switch.
>
> --
> Glynn Clements <glynn at gclements.plus.com>
>




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